nashou
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Post by nashou on Nov 18, 2016 13:22:02 GMT -5
I ordered all the transistors minus the 2sk146's If i need those I may order the 1NF146 from mouser. less shipping charges.
What I might do is replace every resistor too if I have them in stock. I have a 1/4 watt and 1/2 watt kits with lots of values.
Nashou
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nashou
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Post by nashou on Nov 18, 2016 20:21:11 GMT -5
Ok Put everything back in except for TR107 I had -22.26 on -B line
TR105
B=-5.9
C=24.57
E=0
But when I add the half of TR107 to the half that connects to TR103 -B line voltage drops to -12.xx
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Post by mastertech on Nov 18, 2016 20:37:20 GMT -5
Still enjoying working on this stuff?  |
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nashou
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Post by nashou on Nov 18, 2016 20:38:07 GMT -5
Also with tr107 out the Gate of the one half connected to R125 rises slowly over 5-8 minutes to 3.9 volts then slowly drops back down . I didnt have patience to see where it droped to.
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nashou
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Post by nashou on Nov 18, 2016 20:41:22 GMT -5
Yeah real fun but i like the challenge .
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nashou
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Post by nashou on Nov 18, 2016 20:42:19 GMT -5
Also some how TR107 blew both sides. But the one I droped in the Cassis and it may have got damaged in there .
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nashou
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Post by nashou on Nov 19, 2016 8:07:47 GMT -5
How do you test if a transistor is leaky?
Nashou
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Post by mastertech on Nov 19, 2016 14:55:37 GMT -5
For a basic transistor, set your DMM on diode test, put 1 probe on base and other probe on emitter or collector. Depending on transistor type (P or N) you should have flow in 1 direction and "No Flow" in the other direction. And nothing between emitter and collector both directions. Leaking would be if it showed some flow in any direction it is not suppose to. Also note that there are rare occasions where a transistor will only act up when actively in use but test fine with meter.
Other types like SCR, Jfet, Mosfet, testing is different.
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nashou
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Post by nashou on Nov 19, 2016 15:09:02 GMT -5
For a basic transistor, set your DMM on diode test, put 1 probe on base and other probe on emitter or collector. Depending on transistor type (P or N) you should have flow in 1 direction and "No Flow" in the other direction. And nothing between emitter and collector both directions. Leaking would be if it showed some flow in any direction it is not suppose to. Also note that there are rare occasions where a transistor will only act up when actively in use but test fine with meter. Other types like SCR, Jfet, Mosfet, testing is different. So that is why most just change out the transistor since most are dirt cheap. Would it be wise, while I wait for the new transistors, to swap all transistors on the good channel with the bad channel one one at a time to see what happens? of course I'll pull TR108 and TR107. Aslo what I noticed is that On the + side of C111 i get the - voltage reading whereas with C112 i get no voltage. Tr 107 is out but TR108 is in. |
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Post by mastertech on Nov 19, 2016 17:42:38 GMT -5
When tr107 removed your B- is ok, isn't it?
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nashou
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Post by nashou on Nov 19, 2016 17:55:21 GMT -5
When tr107 removed your B- is ok, isn't it? well its -21.75 so not really , it should be -25 . Also just probing around I'l go back to C123 and 122. On C122 the good channel i get no voltage on either side.But on C123 I get -21.48 on the + side and the voltage does the rise , its at about -3.5 when i stop reading starting from about -2.2. Same situation on C113,115 and C114 and C116 just slightly lower voltages on C113,115. It seems something is shorting to that line. TR107 is out. Tr108 is in. I am going to remove TR108 now to compare more evenly. Nashou |
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Post by mastertech on Nov 19, 2016 18:08:56 GMT -5
Yes, remove tr108.
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nashou
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Post by nashou on Nov 19, 2016 18:29:57 GMT -5
ok all voltages seem fine here now. they all are close. -B is still lower than -25 volts. -24.72.
Aslo the gates are close on TR107 and 108. the ones that get a voltage the ( outer) ones.
TR107 is -2.129 Stable
TR 108 is -2.7.33 the jumps up and down to -2.77 ?
Nashou
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Post by mastertech on Nov 19, 2016 19:25:15 GMT -5
Yeah, that is about where we ended up before. The circuit has to be active for it to show up.
How about try this. TR115 still has me bothered. Take tr116 out and put it in TR115 place. Leave tr116 empty and leave TR108 empty. Put in good transistors in tr107 and see what your B- is.
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Post by mastertech on Nov 19, 2016 19:31:17 GMT -5
I just noticed another problem with the schematic. D101 and D102 are installed opposite on the schematic when they should be installed the same. If you get a chance see if you can verify on the board if they are the same or different.
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